A friend suggested that I look at the TRIAK trimaran sailing kayak site.The boat uses a fibreglas(?) gull-wing aka rig with small amas. The amashave small hydrofoils extending outward from the amas.

The TRIAK amas look like toys compared to the AI amas (their displacement has to be very small). I don't know how much stability they would provide on a stiff beam reach.

Would such hydrofoils 'improve' the AI ama performance?

Another 'improvement' to put our DIY list?

Quoting from their website:

Quote:

Key to the TRIAK's performance are the static hydrofoils attached to the outriggers. As the boat heels over the float/ama submerges through the water. The foil provides lift starting around 2-3 knots of boat speed and increases exponentially providing significant lift over 5 knots. Not only do the foils deliver great stability but they allow a manageable outrigger size. Instead of large 5-6' amas both TRIAK amas fit snuggly into the cockpit.

Tidalwave - Like you it makes me wonder what the addition of hydrofoils would haave on the AI.
Can anyone come up with a way to add them and give it a test run

Key to the TRIAK's performance are the static hydrofoils attached to the outriggers. As the boat heels over the float/ama submerges through the water. The foil provides lift starting around 2-3 knots of boat speed and increases exponentially providing significant lift over 5 knots. Not only do the foils deliver great stability but they allow a manageable outrigger size. Instead of large 5-6' amas both TRIAK amas fit snuggly into the cockpit.

Tidalwave - Like you it makes me wonder what the addition of hydrofoils would haave on the AI.Can anyone come up with a way to add them and give it a test run

I would have thought that unless you raise the ama somewhat out the water, to reduce some drag on the ama, the additional drag that a hydrofoil offers, would just slow you down. But in strong wind, you might be able to have more sail out, without burying the ama, and that would make things faster. I wonder if their hydrofoil can be transferred to an ama? Otherwise we have to make one ourselves.

Notice in this pic the ama is buried, and hes also leaning out?

Actually the hydrofoil looks tiny. Am I reading this right? A bit longer than a mower blade?

and here too:

Interestingly, its about the same weight as an AI, maybe a tad more, but 18 inches longer. It has a 40 sq ft sail, and a 40 sq ft spinnaker, where we have 57.5 furling. But its a busy craft, boom, jib/spinnaker and no sign of a furler. Must be able to do something when 40kt hits you 3 km offshore?

Water is rather smooth in this so called "gale" according to their site. Fellow still has to lean out I see.

My personal feeling is it looks very flimsy, and if you have no boat speed, and get hit by a gust, there's no lift to save you. But for sure we can try out a hydrofoil, and I guess to keep the amas capable of folding, you need to have it on the outside. Attaching it to an aka seems logical, but is going to be an issue for folding. I don't like the idea of drilling mounting holes in my ama, frankly. Guess maybe we could make it clamp right around it?

A friend took one out a couple of years ago for a demo. Apparently he capsized twice. They don't have near the stability of the AI. I have the impression that the outboard location of the foils make them primarily for stability enhancement. Fixed in place, they don't appear to be designed to lift the ama out and reduce drag. For the AI, I would imagine you would want the foil under the ama to lift it.

Triak usually appears at the boat show here in San Diego. Nice looking rig, very busy cockpit and definitely set up for sailing. Although produced nearby, they're pretty rare around here -- I've never seen one on the water. It'd be fun to run one against an AI!

I have the impression that the outboard location of the foils make them primarily for stability enhancement. Fixed in place, they don't appear to be designed to lift the ama out and reduce drag. For the AI, I would imagine you would want the foil under the ama to lift it.

Well no. As long as its attached, the uplift will occur. But I think the width of the blades looks like its very unlikely there would be much uplift, but its the first such device I have ever looked at. It just seems very narrow. But I will give some thought to how one could create a mock up.

anyone know why hobie stopped production on the tri foiler were they really dangerous?- who am i kiddin id poop my pants goin that fast

I believe (read it somewhere) its operating 'margins' were a bit limited. It didnt work so well if the sea was a bit choppy and I BELIEVE it wasnt very good in stronger winds. I dont it was 'dangerous' but you really needed exactly the right conditions, not the sort of thing you could leave hauled up on the beach next to your Hobie 16 and not nearly as versatile. If anyone on this forum heard they were 'dangerous', Hobie would have sold out by now!!!!!!

The Triak foils extend outward, making them a bit vulnerable. The big boys are using C shaped retractable ones in boats like Groupama 3, Banque Populaire, and BMW-Oracle's Dogzilla. They curve underneath the amas.